Slut Mode "combat" doesn't do any damage except for orgasm, and that should be more than manageable if you're healing between fights. The enemies leave each time one of them "finishes" with you. As for the map, it is mostly just a straight shot up to the boss. You can explore a bit if you need items or to dodge around enemies, and there's something useful for the boss on the pier toward the end, but otherwise nothing major.